view docs/html/sdljoystickgetaxis.html @ 2321:c5feceb0395e

SetupWindowData in SDL_X11window.c was realloc()ing the display window list and incrementing numwindows even though those are being updated in functions that call this function. The result is that it is possible to get the same window added to the list twice.
author Bob Pendleton <bob@pendleton.com>
date Tue, 04 Mar 2008 23:09:28 +0000
parents 355632dca928
children
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>SDL_JoystickGetAxis</H1
><DIV
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><H2
>Name</H2
>SDL_JoystickGetAxis&nbsp;--&nbsp;Get the current state of an axis</DIV
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>Synopsis</H2
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>Sint16 <B
CLASS="FSFUNC"
>SDL_JoystickGetAxis</B
></CODE
>(SDL_Joystick *joystick, int axis);</CODE
></P
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><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_JoystickGetAxis</TT
> returns the current state of the given <TT
CLASS="PARAMETER"
><I
>axis</I
></TT
> on the given <TT
CLASS="PARAMETER"
><I
>joystick</I
></TT
>.</P
><P
>On most modern joysticks the X axis is usually represented by <TT
CLASS="PARAMETER"
><I
>axis</I
></TT
> 0 and the Y axis by <TT
CLASS="PARAMETER"
><I
>axis</I
></TT
> 1. The value returned by <TT
CLASS="FUNCTION"
>SDL_JoystickGetAxis</TT
> is a signed integer (-32768 to 32768) representing the current position of the <TT
CLASS="PARAMETER"
><I
>axis</I
></TT
>, it maybe necessary to impose certain tolerances on these values to account for jitter. It is worth noting that some joysticks use axes 2 and 3 for extra buttons.</P
></DIV
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CLASS="REFSECT1"
><A
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></A
><H2
>Return Value</H2
><P
>Returns a 16-bit signed integer representing the current position of the <TT
CLASS="PARAMETER"
><I
>axis</I
></TT
>.</P
></DIV
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><A
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><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>Sint16 x_move, y_move;
SDL_Joystick *joy1;
.
.
x_move=SDL_JoystickGetAxis(joy1, 0);
y_move=SDL_JoystickGetAxis(joy1, 1);</PRE
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>See Also</H2
><P
><A
HREF="sdljoysticknumaxes.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickNumAxes</TT
></A
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